Polarisation labelling spectroscopy of rubidium dimer: Highly excited 81∑u+, 91∑u+ and 81∏u states

Excitation spectra of rubidium dimer were investigated in the spectral range cm-1 by polarisation labelling spectroscopy technique. Three hitherto unknown electronic states were observed and assigned as 8, 9 and 8. The experimental findings on the states were compared with theoretical predictions. The investigated electronic states are presently the highest ungerade states of Rb2 known experimentally and the 8 state has not been studied theoretically as yet.